Research and practice of filling technology in fully mechanized working face through the trend roadway

Taking the fully mechanized working face through the trend roadway as the engineering background, the field investigation, theoretical analysis, numerical simulation andindustrial tests were comprehensively used, the instability mechanism of the trend roadway was studied, which pointed out that the depth-span ratio was the key factor affecting the stability of the trend roadway; the four stages with deformation and failure evolution of trend roadway roof were deduced, the principle of timely support and reduction of roof span should be followed for controlling the roof of trend roadway was proposed; comparing the traditional method through the trend roadway from the perspectives of technology and economic benefits, the filling and controlling technology in fully mechanized working face through the trend roadway with the high water material was put forward, the action mechanism of the fillings on the roof of the trend roadway was revealed, and the key parameters of the fillings were identified: the compressive strength of the fillings was 1.0 MPa, and the water-cement mass ratio of the high water material is 8∶1. On this basis, the filling technology and process of the trend roadway were designed. Industrial tests show that during the fully mechanized working face through the trend roadway, the roof is effectively supported by the fillings and the normal coal mining is not significantly affected, the safe mining of coal resources is guaranteed.